Examples of known molding systems are (amongst others): (i) the HyPET (TRADEMARK) Molding System, (ii) the Quadloc (TRADEMARK) Molding System, (iii) the Hylectric (TRADEMARK) Molding System, and (iv) the HyMET (TRADEMARK) Molding System, all manufactured by Husky Injection-molding systems (Location: Canada; Web Site: www.husky.ca).
U.S. Pat. No. 4,272,466 (Inventor: HARRIS; Published: Jun. 9, 1981) discloses a molding-system method for controlling temperature of a plastics extruder that uses a deep well sensor and a shallow well sensor in each temperature control zone along an extruder barrel. The temperature indications of these sensors are not combined. The shallow well sensor detects temperature near the barrel surface. An associated computer compares the sensor temperature with a preset temperature set point. The differences between the detected and set temperature are used by the computer to effect heating or cooling of a temperature control zone. Each deep well sensor is located proximate a bore (that is, a melt pathway) in which the plastic is moved. The deep well sensor temperature indication is compared with the set point of a second computer. Based on variations of the temperature relative to the set point, an error signal is generated, and in turn the output of a heater is adapted. The computer compares a set point with that of the melt temperature, and modifies the set points of the several zones along the extruder barrel to correct the melt temperature.
U.S. Pat. No. 4,548,341 (Inventor: HAMBLETON; Published: Oct. 22, 1985) discloses a plastic injection apparatus that has: (i) a barrel, (ii) a plastic working screw located in the bore (that is, a melt pathway) of the barrel, (iii) a nozzle for injecting melted plastic from out of the front of the bore to a mold, and (iv) a plurality of axially spaced heater bands ringing the barrel over its length. The heat control for the plastic injection apparatus is improved by: (i) subdividing the barrel into a rear part and a front part, (ii) impeding an outward flow of heat energy from the rear part by using a thermal insulating material and by using a heat reflective surface, and (iii) promoting the outward flow of heat energy from the front part by using a cooling means and by using a tubular barrel cover, which encloses the front part. The tubular barrel cover has an inner surface and an outer surface, which are heat absorptive and heat reflective, respectively. In one embodiment, the thermal insulating material is incorporated in a tubular insulating shroud that encloses the heater bands in the rear part.
U.S. Pat. No. 5,272,644 (Inventor: KATSUMATA et al; Published: Dec. 21, 1993) discloses a heating-control apparatus that is used for controlling a heating temperature, especially for heating a resin in the injection molding machine. The heating-control apparatus includes: (i) a control device for controlling a heating means and the heating state of a heated barrel, and (ii) a condition compensating device for issuing a compensation input to the heating means in response to a reset of the control device (depending on the kinds of resin materials and molding conditions) so as to prevent: (i) insufficient moldability in the injection molding machine, and (ii) a deterioration of the resin.
U.S. Pat. No. 5,776,513 (Inventor: HONJO et al; Published: Jul. 7, 1998) discloses a device for: (i) controlling temperature of a nozzle of an injection molding machine, (ii) maintaining uniform temperature over the nozzle, and (iii) preventing stringiness or drooling of melted resin. A temperature-monitoring computer is used for controlling temperature at a front portion and at a rear portion of the nozzle by controlling the electric power supplied to a front heater and to a rear heater by using an “ON-OFF” operation of a relay and of a voltage regulator. The relay and the voltage regulator are used for controlling voltage applied to (by use of an operational amplifier): (i) the front heater, or (ii) the rear heater. The operational amplifier is used for detecting differences of temperature at the front portion and the rear portion of the nozzle.
U.S. Pat. No. 6,104,006 (Inventor: KIMURA et al; Published: Aug. 15, 2000) discloses a molding-system method and an apparatus for programmed temperature control of a heating barrel in which a thermal sensor can be set selectively in a plurality of sensor holes on a feeding zone of the heating barrel. By sensing the temperature at the most appropriate position in the feeding zone, the molding injection process is adapted to various resins with different properties, which prevents clogging of resin in the heating barrel and changed color of molded articles.